British health experts have flown out to African countries at the heart of the Ebola crisis in an effort to help contain the growing crisis.

Public Health England revealed ten of their health workers will have been flown into hotspots for the disease by the end of August to support Government's in the region who are struggling to contain the disease.

They will offer advice on how to keep track of the number of people infected and methods to control the outbreak. While the experts will 'categorically' not be directly treating patients they will offer laboratory testing.

The help comes as the World Health Organisation declared the outbreak an international health emergency.

Duncan Selbie, the head of Public Heath England has also warned that Britain’s defence systems against Ebola need to be “watertight”.

Mr Selbie said that the UK is “unlikely to see many” cases of Ebola but said that the authorities need to be prepared so that they can “manage it promptly and appropriately”.

However he suggested British hospitals, airports and institutions must be ready to immediately “detect, diagnose and manage” the illness if anyone infected with the virus arrives in the UK.

Mr Selbie said: “Although it is not transmissible in the same way as flu because it is not airborne and we are unlikely to see many, if any, cases here, we nonetheless need to ensure our defence systems are watertight so that if someone does return to the UK with the infection, we can detect, diagnose and manage it promptly and appropriately."

He has told GPs to "remain vigilant for unexplained illness" in those who have visited the affected area, and actions to take in the event of a possible case.

He added: “Some of our experts have gone out to the region to support teams on the ground. I am very grateful to everyone for their tremendous work and especially those who have gone out to Africa.”

Dr Brian McCloskey, director of global health at PHE, said: "Though it is possible a case could be identified in the UK in a person returning from an affected country, this is unlikely.

"Even if a case were identified, there is minimal risk of it spreading across the general population as UK hospitals are well prepared to handle infectious diseases. Ebola causes far more harm in countries with less developed healthcare facilities and public health capacity."

The WHO made the decision to declare a international health emergency after a two-day emergency session behind closed doors in Geneva. It means global travel restrictions may be put in place to halt its spread as the overall death toll nears 1,000.

The move comes as US health authorities admitted on Thursday that Ebola's spread beyond west Africa was "inevitable", and after medical charity Medecins Sans Frontieres (MSF) warned that the deadly virus was now "out of control" with more than 60 outbreak hotspots.

WHO director Dr Margaret Chan appealed for greater international aid for the countries worst hit by the outbreak.

"The outbreak is moving faster than we can control it," she said.

British doctor confident he can stay safe while treating Ebola victims